1. Technical Field
This invention relates to signal processing systems. In particular, this invention relates to a signal processing system which imparts a measure of robustness against tonal noise to other signal processing systems.
2. Related Art
Most if not all signal processing systems must intelligently handle input signal noise. The input signal noise may mask, corrupt, distort or otherwise detrimentally affect desired components of the input signal. Input signal noise also may mimic desired input signal components and increase the difficulty of identifying, removing, or compensating for the input signal noise, regardless of the signal processing system or its purpose.
Tonal noise is one form of noise which mimics desired input signal components in some applications. For example, speech processing systems commonly detect and process voice signal components which contain harmonic activity. Vowel sounds and certain consonants exhibit characteristic tonal content which the processing system employs to determine when an individual is speaking, what they are speaking, or other characteristics of the speech.
A speech processing system which examines an input signal for desired signal content may interpret the tonal noise as speech, may isolate a segment of the input signal with the tonal noise, and may attempt to process the tonal noise. The speech processing system consumes valuable computational resources not only to isolate the segment, but also to process the segment and take action based on the result of the processing. In a speech recognition system, the system may interpret the tonal noise as a voice command, execute the spurious command, and responsively take actions that were never intended.
There is a need for a system that provides tonal noise robustness for signal processing systems.